Durometer



S. KORNBLAU June 9, 1964 DUROMETER 2 Sheets-Sheet 1 Filed Jan. 29, 1962 S. KORNBLAU June 9, 1964 DUROMETER 2 Sheets-Sheet 2 Filed Jan. 29, 1962 F/GJO United States Patent 3,136,153 DUROMETER Sol Kornblau, Brooklyn, N.Y., assignor to The Shore Instrument 8; Mfg. (30., Jamaica, N.Y., a corporation of New York Filed Jan. 29, 1962, Ser. No. 169,511 3 Claims. (CI. 73-81) This invention relates to an improved durometer and more particularly to a durometer provided with a novel saddle adjustment of the mainsprings.

In the Shore Patent 2,453,042 there is described a durometer having the fundamental operating elements of this invention.

However, in this prior invention of Shore the adjustment of the parallel disposed mainsprings to meet specification standards was a most tedious and painstaking procedure. Thus to calibrate the mainsprings it was often necessary to cut through the mainsprings part way if the readings were too low or to dismantle the instrument and add stiffener components if the readings were high. Clearly, such a method is crude, time consuming and in some cases entirely unsatisfactory.

According to this invention at least one spring is slotted along its length and a fixed slotted saddle is disposed adjacent thereto and slidable clamp means are secured through said slots and to said spring and said saddle thereby in effect lengthening or shortening the eifective or operative spring length to adjust said spring to the spring qualities desired.

This invention is illustrated by a plurality of illustrative embodiments but it is not to be limited to these embodiments.

These embodiments are shown in the accompanying drawing in which;

FIG. 1 is a front View of one embodiment of the durometer with the dial broken-away in part to show the operative mechanism,

FIG. 2 is a view taken along line 22 of FIG. 1,

FIG. 3 is a view taken along line 33 of FIG. 1,

FIG. 4 is a bottom view of the operative spring mechanism showing one type of fixed saddle disposed in parallel contiguous relationship to a spring,

FIG. 5 is an end view of the operative spring mechanism showing the manner of securing the spring to a fixed support,

FIG. 6 is a view similar to FIG. 1 of another embodimerit,

FIG. 7 is a vertical section view taken on line 77 of FIG. 6,

FIG. 8 is a transverse section view taken on line 88 of FIG. 6,

FIG. 9 is a bottom view of a modified saddle and a similar view to FIG. 4,

FIG. 10 is an end View of the operative spring mechanism and taken on line 1010 of FIG. 6, and

FIG. 11 is a section view taken substantially on line 1111 of FIG. 10 and showing the manner of using an elf-center aperture to effect a firm spring seizure to the frame.

In as much as the apparatus shown in FIGS. 1 to 3 inclusive and FIGS. 6 to 8 inclusive is shown in the Shore Patent 2,453,042 it will be described in only a general manner herein.

The durometer includes a casing 10 which preferably is an integral casing as shown in FIG. 7, or it may be a two piece casing as shown in FIGS. 1 and 2 consisting of a cylindrical casing 10X and a foot element 10Y secured thereto by conventional screws.

The durometers comprise a case assembly 11 which includes the casing 10, a bezel 12, a glass face plate 13, a dial 14, and a handle knob 15.

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In FIGS. 1 to 4 a frame plate 16 is secured to the back wall of the casing by conventional means such as a metal screw.

In FIGS. 6 to 11 a modified unitary frame plate 16X is employed.

In this invention preferably both of the leaf springs 17 are provided at their rearward portion with longitudinal slots, although a one slotted spring modification is operable and wherein the slotted saddle is disposed adjacent to this single slotted spring.

The forward or moveable portion of the parallel disposed springs 17 are not slotted and they are secured to support means to which an angular plate 18 is secured. The angular plate 18 is provided with an adjustable indentor pin 19.

As shown in the drawing and in the Shore patent a pinion assembly 20 is mounted between the rear frame 16 or 16X and a front support plate 21. The pinion assembly being old art will not be described further since it is of conventional latch spring loaded manufacture and secured to the dial pointer shown in dotted outline FIGS. 1to3and7to 8.

Also as shown in the Shore patent a segment gear 22 is meshed with the gear of the pinion assembly 20.

Turning now to the embodiment shown in FIGS. 1 to S inclusive and which for convenience will be called the first form of the embodiment of the invention, it will be seen that a rigid saddle bar 23 is secured fixedly as by rivet pins 24 to the rearward spring support block 25, and that block 25 is firmly secured by metal screws 26 to the frame 16.

The saddle bar 23 is provided with a linear or longitudinal slot 27 disposed in superimposed relationship to the linear slot in the adjacent spring.

An apertured clamping plate 28 is disposed on the spring 17 and a threaded bolt 29 is passed through the aperture of the plate 28 and the slots of the spring 17 and the saddle bar 23, and a nut 30 is secured to its end and firmly against the saddle 23. Clearly the clamping plate 28 may be slid the length of the slots of the superimposed elements 17 and 23 and since the saddle bar is rigidly secured to block 25, the overall effect is that of making the length of the effective spring shorter or longer as desired.

The forward end of the saddle bar 23 is provided with a threaded aperture in which a threaded adjustment bolt 31 is disposed. This adjustment bolt is locked in place after adjustment by means of a threaded lock bolt 32 disposed in a threaded hole located at a right angle to the aperture of bolt 31 and communicating therewith. The adjustment bolt 31 serves to raise the spring 17 out of planar contact with the saddle bar and to adjust the spring qualities as needed in the calibration of the durometer.

As shown in FIG. 5, the springs 17 are located in suitable recesses in the top and bottom of the block 25 to prevent lateral movement and are firmly secured through suitable apertures and bolts 33 to said block 25.

Turning now to the preferred embodiment of this invention, which is shown in FIGS. 6 to 11 of the drawing, the frame 16X is provided with a novel and distinctive construction in as much as it is of a unitary nature. In short, the slotted saddle bar of the preferred embodiment is integral with the frame 16X. 7

As shown in FIG. 10, the frame 16X is provided with an integral top horizontal flange 34 and a corresponding integral bottom parallel disposed horizontal flange 35.

The bottom integral flange, FIGS. 8 and 11, extends inwardly towards the plate 18 and towards the pinion assembly 20 located at the center of the dial and is provided with a suitable linear slot 36 disposed beneath a similar slot in the adjacent leaf spring 17 (FIG. 9). An

apertured clamping plate 37 is provided with an integral depending guide portion 33, thereby guiding and retaining the clamping plate 37 at a right angle .to the slot 36. A threaded bolt 39 is disposed through the aperture of the clamping plate and the slot in the adjacent spring -17 and the slot 36 of the flange 35. Clearly, the flwge 35 of the preferred embodiment substitutes for the saddle bar 23 of the embodiment of FIGS. 1 to 5.

A nut 40 is threaded onto the protruding-end of the bolt 3% thereby clamping the spring E7 to the flange 35. Obviously the clamping unit consisting of the integral clamping plate and the bolt and nut combination 39 and 40 is slidable along the slot of the flange 35 so as to permit selective clamping of the suitably located spring 17 to its adjacent flange 35. Preferably a lock washer 41 is used in connection with the nut 4 (FIG. 9) to effect a rigid locking of the nut and bolt combination to the flange 35.

In the preferred embodiment of-FIGS. 6 to 11, the solid metal block of the first embodiment is replaced in part by a pair of spaced-apart vertically disposed metal cylinders 42, through which the threaded bolts 33 are disposed. As shown in PEG. 11, the apertures in the rearward portion of both springs 17 are disposed in slight of-center relationship to the apertures in the frame flanges 34 and 35. Thus the firm screwing of bolts 33 causes the springs to be pulled forward so that the bent ends 43 of the springs 17 are firmly pulled forward toward the pinion assembly 2%. In this manner there is produced a firm seizure of a respective end 43 of a spring 17 to an end Wall of a respective flange 34 and 35.

A pair of spaced-apart pillars 42 is also used to separate the front ends of the parallel spaced-apart springs 17 in the preferred embodiment of this invention, in lieu of the solid metal block 44 (FIG. 2) of the first embodi ment. As shown in FIGS. 2 and 3, a pin 45 is disposed in a suitable groove in front block 44, said pin 45 being fixedly secured to the segment gear 22. which actuates the pinionassembly 2d and thus the dial indicator. A conventional ratio adjusting link 46 is secured to the segment gear 22 in both embodiments of this invention.

Since a pair of pillars 42 are used at the front portion of springs 17 to keep them apart in parallel relationship and are secured by a pair of threaded bolts 33 to angular bar 18, a guide plate 43 is provided to retain the pin 45 in a suitable slot 49 therein. In both embodiments and as shown in the Shore patent, suitable conventional spacer bars 543 are used to keep the front support plate 21 in spaced relationship to the frame 16X or 16 as the case may be. Also a conventional rotary journal 51 is employed in both embodiments in the manner taught in the Shore patent.

Another and important feature of the preferred embodiment'is the provision of a rest point for the forward end of the bottom spring 17 by the provision of an integral extension 52 of the frame 16X and the further provision of a stationary post 54 disposed at a right angle to said extension 52.

The post 54 is provided with a threaded aperture in which a threaded bolt 31 is. disposed at a right angle to the post. A locking threaded bolt 32 is disposed in a threaded cavity communicating with said threaded aperture. Clearly, bolt 31 performs the same function in both embodiments of this invention, namely as a rest point below which the forward end of the adjacent spring 17 can not move.

Accordingly, this invention permits an easy and rapid adjustment of the durometer spring characteristics to those desired in the calibration of the instrument by means of a selective clamping action of at least one of the two parallel leaf springs therein.

This invention has been shown and described by means of two embodiments thereof, but it is not to be limited to these embodiments as it is of a more generic scope.

I claim:

1. In a cylindrical dial durometer having a vertical fiat frame secured to a casing, a pair of longitudinal fiat top and bottom horizontally disposed spaced-apart leaf springs, front separator means for said springs, rear sep arator means for said springs secured to said frame, a depending indentor pin engaging the unsecured moveable end of said leaf springs, an actuating pin fixedly diseach having a pair aperture and each provided with bent ends, a pair of tubudue to engagement with said off-set posed in said moveable end of said leaf springs, a conventional slotted segment gear assembly engaging said pin anda conventional dial pin opinion assembly engaging said gear, the calibration improvement comprising a bottom spring having a longitudinal slot therein adjacent said rear separator means, an immoveable longitudinal plate having a longitudinal slot therein secured to said rear separator means below and adjacent to said bottom spring, and slideable clamping means threaded through said slot of said spring and said plate for clamping selectively said spring to said plate.

2. The durometer of claim 1 wherein said longitudinal plate is integral with said frame and at a right angle thereto.

3. The durometer of claim 2 comprising a flange integral with said frame, at a right angle thereto and disposed in suitable spaced-apart relationship to said integral longitudinal plate, said flange and said plate having suitable pairs of bolt receiving apertures therein, said springs of suitably large off-set bolt receiving lar pillars vertically disposed suitably about said apertures between said springs and a pair of bolts disposed through said apertures of said flange, plate and springs whereby tightening of said bolts pulls said springs tautly apertures thereof.

References Qited'in the file of this patent UNITED STATES PATENTS 2,324,586 Klein et al. July 20, 1943 2,453,042 Shore Nov. 2, 1948 2,974,521 Phelps Mar. 14, 1961 2,981,100 Johnson Apr. 25,1961 3,047,084 Vogel July 31, 1962 

1. IN A CYLINDRICAL DIAL DUROMETER HAVING A VERTICAL FLAT FRAME SECURED TO A CASING, A PAIR OF LONGITUDINAL FLAT TOP AND BOTTOM HORIZONTALLY DISPOSED SPACED-APART LEAF SPRINGS, FRONT SEPARATOR MEANS FOR SAID SPRINGS, REAR SEPARATOR MEANS FOR SAID SPRINGS SECURED TO SAID FRAME, A DEPENDING INDENTOR PIN ENGAGING THE UNSECURED MOVEABLE END OF SAID LEAF SPRINGS, AN ACTUATING PIN FIXEDLY DISPOSED IN SAID MOVEABLE END OF SAID LEAF SPRINGS, A CONVENTIONAL SLOTTED SEGMENT GEAR ASSEMBLY ENGAGING SAID PIN AND A CONVENTIONAL DIAL PIN OPINION ASSEMBLY ENGAGING SAID GEAR, THE CALIBRATION IMPROVEMENT COMPRISING A BOTTOM SPRING HAVING A LONGITUDINAL SLOT THEREIN ADJACENT SAID REAR SEPARATOR MEANS, AN IMMOVEABLE LONGITUDINAL PLATE HAVING A LONGITUDINAL SLOT THEREIN SECURED TO SAID REAR SEPARATOR MEANS BELOW AND ADJACENT TO SAID BOTTOM SPRING, AND SLIDEABLE CLAMPING MEANS THREADED THROUGH SAID SLOT OF SAID SPRING AND SAID PLATE FOR CLAMPING SELECTIVELY SAID SPRING TO SAID PLATE. 